1.
Microscope
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A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy, microscopic means invisible to the eye unless aided by a microscope. There are many types of microscopes, the most common is the optical microscope, which uses light to image the sample. Other major types of microscopes are the microscope, the ultramicroscope. The earliest microscopes were single lens magnifying glasses with limited magnification which date at least as far back as the wide use of lenses in eyeglasses in the 13th century. Compound microscopes, which combine an objective lens with an eyepiece to view a real image, the actual inventor of the compound microscope is unknown although many claims have been made over the years. These include what may be a claim by the son of Zacharias Janssen that his father invented the microscope and telescope as early as 1590. Historians note the compound microscope did not appear in the Netherlands until the 1620s, giovanni Faber coined the name microscope for the compound microscope Galileo submitted to the Accademia dei Lincei in 1625. The first detailed account of the construction of living tissue based on the use of a microscope did not appear until 1644, in Giambattista Odiernas Locchio della mosca. It was not until the 1660s and 1670s that the microscope was used extensively for research in Italy, marcello Malpighi in Italy began the analysis of biological structures, beginning with the lungs. Robert Hookes Micrographia had an impact, largely because of its impressive illustrations. A significant contribution came from Antonie van Leeuwenhoek who achieved up to 300 times magnification using a single lens microscope. He sandwiched a very small glass ball lens between the holes in two metal plates riveted together, and with a needle attached to mount the specimen. Then, Van Leeuwenhoek re-discovered red blood cells and spermatozoa, on 9 October 1676, he reported the discovery of micro-organisms. The performance of light microscopy depends as much on how the sample is illuminated as on how it is observed, early instruments were limited until this principle was fully appreciated and developed, and until electric lamps were available as light sources. In 1893 August Köhler developed a key principle of sample illumination, Köhler illumination and this method of sample illumination produces even lighting and overcomes the limited contrast and resolution imposed by early techniques of sample illumination. In the early 20th century a significant alternative to light microscopy was developed, ernst Ruska started development of the first electron microscope in 1931 which was the transmission electron microscope. The transmission electron microscope works on the principle as an optical microscope but uses electrons in the place of light
2.
Printer (computing)
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In computing, a printer is a peripheral which makes a persistent human-readable representation of graphics or text on paper or similar physical media. The worlds first computer printer was a 19th-century mechanically driven apparatus invented by Charles Babbage for his difference engine, the plotter was used for those requiring high quality line art like blueprints. Laser printers using PostScript mixed text and graphics, like dot-matrix printers, by 1990, most simple printing tasks like fliers and brochures were now created on personal computers and then laser printed, expensive offset printing systems were being dumped as scrap. The HP Deskjet of 1988 offered the same advantages as laser printer in terms of flexibility, inkjet systems rapidly displaced dot matrix and daisy wheel printers from the market. By the 2000s high-quality printers of this sort had fallen under the price point. Even the desire for printed output for offline reading while on mass transit or aircraft has been displaced by e-book readers, today, traditional printers are being used more for special purposes, like printing photographs or artwork, and are no longer a must-have peripheral. Starting around 2010, 3D printing became an area of intense interest and these devices are in their earliest stages of development and have not yet become commonplace. Personal printers are designed to support individual users, and may be connected to only a single computer. These printers are designed for low-volume, short-turnaround print jobs, requiring minimal setup time to produce a copy of a given document. However, they are generally slow devices ranging from 6 to around 25 pages per minute, however, this is offset by the on-demand convenience. Some printers can print documents stored on cards or from digital cameras. Networked or shared printers are designed for high-volume, high-speed printing and they are usually shared by many users on a network and can print at speeds of 45 to around 100 ppm. The Xerox 9700 could achieve 120 ppm, a virtual printer is a piece of computer software whose user interface and API resembles that of a printer driver, but which is not connected with a physical computer printer. It is called a printer by analogy with a printer which produces a two-dimensional document by a similar process of depositing a layer of ink on paper. The choice of print technology has an effect on the cost of the printer and cost of operation, speed, quality and permanence of documents. Some printer technologies dont work with certain types of physical media, cheques can be printed with liquid ink or on special cheque paper with toner anchorage so that alterations may be detected. The machine-readable lower portion of a cheque must be printed using MICR toner or ink, banks and other clearing houses employ automation equipment that relies on the magnetic flux from these specially printed characters to function properly. The following printing technologies are found in modern printers, A laser printer rapidly produces high quality text
3.
Dot matrix
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A dot matrix is a 2-dimensional patterned array, used to represent characters, symbols and images. Every type of modern technology uses dot matrices for display of information, including phones, televisions. They are also used in textiles with sewing, knitting, in printers, the dots are usually the darkened areas of the paper. In displays, the dots may light up, as in an LED, CRT, or plasma display, or darken, as in an LCD. As an impact printer, the term refers to low-resolution impact printers, with a column of 8,9 or 24 pins hitting an ink-impregnated fabric ribbon, like a typewriter ribbon. It was originally contrasted with both daisy wheel printers and line printers that used fixed-shape embossed metal or plastic stamps to mark paper. Impact printers survive where multi-part forms are needed, as the pins can impress dots through multiple layers of paper to make a carbonless copy, all types of electronic printers typically generate image data as a two-step process. External raster image processing was possible such as to print a graphical image, depending on the printer technology the dot size or grid shape may not be uniform. Some printers are capable of producing smaller dots and will intermesh the small dots within the larger ones for antialiasing. A dot matrix is useful for marking materials other than paper, in manufacturing industry, many product marking applications use dot matrix inkjet or impact methods. This can also be used to print 2D matrix codes, e. g. Datamatrix. Although the output of modern computers is generally all in the form of dot matrices, vector data encoding requires less memory and less data storage, in situations where the shapes may need to be resized, as with font typefaces. For maximum image quality using only dot matrix fonts, it would be necessary to store a separate dot matrix pattern for the different potential point sizes that might be used. Instead, a group of vector shapes is used to render all the specific dot matrix patterns needed for the current display or printing task. An LED matrix or LED display is a large, low-resolution form of dot-matrix display and it consists of a 2-D diode matrix with their cathodes joined in rows and their anodes joined in columns. By controlling the flow of electricity through each row and column pair it is possible to control each LED individually, by multiplexing, scanning across rows, quickly flashing the LEDs on and off, it is possible to create characters or pictures to display information to the user. By varying the rate per LED, the display can approximate levels of brightness. Multi-colored LEDs or RGB-colored LEDs permit use as an image display
4.
Inkjet printing
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Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper, plastic, or other substrates. Inkjet printers are the most commonly used type of printer, the concept of inkjet printing originated in the 20th century, and the technology was first extensively developed in the early 1950s. Starting in the late 1970s inkjet printers that could reproduce digital images generated by computers were developed, mainly by Epson, Hewlett-Packard, in the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales, Canon, HP, Epson, and Brother. The emerging ink jet material deposition market also uses inkjet technologies, typically printheads using piezoelectric crystals, the technology has been extended and the ″ink″ can now also comprise living cells, for creating biosensors and for tissue engineering. There are two main technologies in use in contemporary inkjet printers, continuous and Drop-on-demand, the continuous inkjet method is used commercially for marking and coding of products and packages. In 1867 Lord Kelvin patented the syphon recorder, which recorded telegraph signals as a trace on paper using an ink jet nozzle deflected by a magnetic coil. The first commercial devices were introduced in 1951 by Siemens, the ink droplets are subjected to an electrostatic field created by a charging electrode as they form, the field varies according to the degree of drop deflection desired. This results in a controlled, variable electrostatic charge on each droplet, charged droplets are separated by one or more uncharged guard droplets to minimize electrostatic repulsion between neighbouring droplets. The more highly charged droplets are deflected to a greater degree, only a small fraction of the droplets is used to print, the majority being recycled. CIJ is one of the oldest ink jet technologies in use and is fairly mature, viscosity is monitored and a solvent is added to counteract solvent loss. Drop-on-demand is divided into thermal DOD and piezoelectric DOD, most consumer inkjet printers, including those from Canon, Hewlett-Packard, and Lexmark, use the thermal inkjet process. Vaughts work started in late 1978 with a project to develop fast, low-cost printing, the team at HP found that thin-film resistors could produce enough heat to fire an ink droplet. Two years later the HP and Canon teams found out about each others work, in the thermal inkjet process, the print cartridges consist of a series of tiny chambers, each containing a heater, all of which are constructed by photolithography. The inks involved are usually water-based and use either pigments or dyes as the colorant, the inks must have a volatile component to form the vapor bubble, otherwise droplet ejection cannot occur. As no special materials are required, the print head is generally cheaper to produce than in other inkjet technologies, most commercial and industrial inkjet printers and some consumer printers use a piezoelectric material in an ink-filled chamber behind each nozzle instead of a heating element. When a voltage is applied, the material changes shape, generating a pressure pulse in the fluid. A DOD process uses software that directs the heads to apply between zero and eight droplets of ink per dot, only where needed, piezo inkjet technology is often used on production lines to mark products. For instance, the date is often applied to products with this technique, in this application the head is stationary
5.
Thermal printing
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The coating turns black in the areas where it is heated, producing an image. Two-colour direct thermal printers can print both black and an additional colour by applying heat at two different temperatures, thermal transfer printing is a very different method that uses a heat-sensitive ribbon instead of heat-sensitive paper, but uses similar thermal print heads. The printer sends a current to the heating elements of the thermal head. The heat activates the thermo-sensitive coloring layer of the thermosensitive paper, such a printing mechanism is known as a thermal system or direct system. The heating elements are arranged as a matrix of small closely spaced dots—thermal printers are actually dot-matrix printers. The paper is impregnated with a mixture of a dye and a suitable matrix, a combination of a fluoran leuco dye. Controller boards are embedded with firmware to manage the thermal printer mechanisms, the firmware can manage multiple bar code types, graphics and logos. They enable the user to choose between different resident fonts and character sizes. Controller boards can drive various sensors such as low, paper out, door open and so on. For point of sale application some boards can also control the cash drawer, thermal printers print more quietly and usually faster than impact dot matrix printers. They are also smaller, lighter and consume less power, making them ideal for portable and its efficiency can be utilized in retail sectors. Roll-based printers can be rapidly refilled and they often used unusually-sized supplies and were often used for making permanent records of information in the computer, rather than for correspondence. Through the 1990s many fax machines used thermal printing technology, thermal Receipt Printers are very efficient and quick. Its efficiency can be utilized in retail sectors, thermal printers are still commonly used in seafloor exploration and engineering geology due to their portability, speed, and ability to create continuous reels or sheets. Typically, thermal printers found in applications are used to print realtime records of side scan sonar. In data processing, thermal printers are used to quickly create hard copies of continuous seismic or hydrographic records stored in digital SEG Y or XTF form. The Game Boy Printer, released in 1998, was a thermal printer used to print out certain elements from some Game Boy games. Early formulations of the coating used in thermal paper were sensitive to incidental heat, abrasion, friction, light
6.
Laser printing
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Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back, the drum then selectively collects electrically charged powdered ink, and transfers the image to paper, which is then heated in order to permanently fuse the text and/or imagery. As with digital photocopiers, laser printers employ a xerographic printing process, however, laser printing differs from analog photocopiers in that the image is produced by the direct scanning of the medium across the printers photoreceptor. This enables laser printing to copy images more quickly than most photocopiers, invented at Xerox PARC in the 1970s, laser printers were introduced for the office and then home markets in subsequent years by IBM, Canon, Xerox, Apple, Hewlett-Packard and many others. Over the decades, quality and speed have increased as price has fallen, in the 1960s, the Xerox Corporation held a dominant position in the photocopier market. In 1969, Gary Starkweather, who worked in Xeroxs product development department, had the idea of using a beam to draw an image of what was to be copied directly onto the copier drum. After transferring to the recently formed Palo Alto Research Center in 1971, in 1972, Starkweather worked with Butler Lampson and Ronald Rider to add a control system and character generator, resulting in a printer called EARS —which later became the Xerox 9700 laser printer. The first commercial implementation of a printer was the IBM3800 in 1976. It was designed for data centers, where it replaced line printers attached to mainframe computers, the IBM3800 was used for high-volume printing on continuous stationery, and achieved speeds of 215 pages per minute, at a resolution of 240 dots per inch. Over 8,000 of these printers were sold, the Xerox 9700 was brought to market in 1977. Unlike the IBM3800, the Xerox 9700 was not targeted to any particular existing printers. The Xerox 9700 excelled at printing high-value documents on paper with varying content. In 1979, inspired by the Xerox 9700s commercial success, Japanese camera and optics company, Canon, developed a low-cost, desktop laser printer, Canon then began work on a much-improved print engine, the Canon CX, resulting in the LBP-CX printer. Lacking experience in selling to computer users, Canon sought partnerships with three Silicon Valley companies, Diablo Data Systems, Hewlett-Packard, and Apple Computer, the first laser printer designed for office use reached market in 1981, the Xerox Star 8010. The system used a metaphor that was unsurpassed in commercial sales. Although it was innovative, the Star workstation was an expensive system, affordable only to a fraction of the businesses. The first laser printer intended for mass-market sales was the HP LaserJet, released in 1984, it used the Canon CX engine, the LaserJet was quickly followed by printers from Brother Industries, IBM, and others. First-generation machines had large photosensitive drums, of greater than the loaded papers length
7.
Typewriter
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A typewriter is a mechanical or electromechanical machine for writing characters similar to those produced by printers movable type. A typewriter operates by means of keys that strike a ribbon to transmit ink or carbon impressions onto paper, typically, a single character is printed on each key press. The machine prints characters by making ink impressions of type elements similar to the used in movable type letterpress printing. At the end of the century, the term typewriter was also applied to a person who used a typing machine. After its invention in the 1860s, the quickly became an indispensable tool for practically all writing other than personal handwritten correspondence. It was widely used by writers, in offices. As with the automobile, telephone, and telegraph, a number of people contributed insights, historians have estimated that some form of typewriter was invented 52 times as thinkers tried to come up with a workable design. Some of the early typing instruments, In 1575 an Italian printmaker, Francesco Rampazzetto, invented the scrittura tattile, in 1714, Henry Mill obtained a patent in Britain for a machine that, from the patent, appears to have been similar to a typewriter. In 1802 Italian Agostino Fantoni developed a particular typewriter to enable his blind sister to write, in 1808 Italian Pellegrino Turri invented a typewriter. He also invented carbon paper to provide the ink for his machine, in 1823 Italian Pietro Conti di Cilavegna invented a new model of typewriter, the tachigrafo, also known as tachitipo. In 1829, William Austin Burt patented a machine called the Typographer which, the Science Museum describes it merely as the first writing mechanism whose invention was documented, but even that claim may be excessive, since Turris invention pre-dates it. Even in the hands of its inventor, this machine was slower than handwriting, Burt and his promoter John D. Sheldon never found a buyer for the patent, so the invention was never commercially produced, because the typographer used a dial, rather than keys, to select each character, it was called an index typewriter rather than a keyboard typewriter. Index typewriters of that era resemble the squeeze-style embosser from the 1960s more than they resemble the modern keyboard typewriter, by the mid-19th century, the increasing pace of business communication had created a need for mechanization of the writing process. Stenographers and telegraphers could take down information at rates up to 130 words per minute, from 1829 to 1870, many printing or typing machines were patented by inventors in Europe and America, but none went into commercial production. Charles Thurber developed multiple patents, of which his first in 1843 was developed as an aid to the blind, in 1855, the Italian Giuseppe Ravizza created a prototype typewriter called Cembalo scrivano o macchina da scrivere a tasti. It was a machine that let the user see the writing as it was typed. In 1861, Father Francisco João de Azevedo, a Brazilian priest, made his own typewriter with basic materials and tools, such as wood, in that same year the Brazilian emperor D
8.
Daisy wheel printing
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Daisy wheel printing is an impact printing technology invented in 1969 by David S. Lee at Diablo Data Systems. Daisy wheel printing was used in typewriters, word processors and computers from 1972. The daisy wheel is considered to be so named because of its resemblance to the daisy flower, by 1980 daisy wheel printers had become the dominant technology for high-quality print. Dot-matrix impact, thermal, or line printers were used where speed was required. Daisy wheel technology is now only in some electronic typewriters. In 1889 Arthur Irving Jacobs patented a daisy wheel design that was used on the Victor index typewriter, a. H. Reiber of Teletype Corporation received U. S. Patent 2,146,380 in 1939 for a daisy wheel printer, in 1972 a team at Diablo Systems led by engineer David S.4 cps. Xerox acquired Diablo that same year, following which Lee departed to set up Qume Corporation in 1973, xeroxs Office Product Division had already been buying Diablo printers for its Redactron text editors. After 7 years trying to make Diablo profitable, the OPD focused on developing and selling the Diablo 630 which was bought by companies such as Digital Equipment Corporation. The Diablo 630 could produce letter quality output as good as that produced by an IBM Selectric or Selectric-based printer, a further advantage was that it supported the entire ASCII printing character set. Its servo-controlled carriage also permitted the use of proportional spaced fonts, Xerox later adapted Diablos daisy wheel technology into a typewriter that sold for less than $50. An automated factory was built near Dallas that took less than 30 minutes to assemble a Xerox typewriter, the Xerox typewriter was well received but never achieved the projected sales numbers due to the advent of the PC and word processing software. The typewriter was modified to be compatible with PCs but the engineering which made it a low cost device reduced its flexibility. The heart of the system is a metal or plastic daisy wheel holding an entire character set as raised characters moulded on each petal. In use a servo motor rotates the wheel to position the required character between the hammer and the ribbon. The solenoid-operated hammer then fires, driving the character type onto the ribbon, the daisy wheel and hammer are mounted on a sliding carriage similar to that used by dot matrix printers. Different typefaces and sizes can be used by replacing the daisy wheel, however, printing a document with frequent font changes and thus requiring frequent wheel changes was a tedious task. Like all other impact printers, daisy wheel printers are noisy, most daisy-wheel printers could print a line and then, using built-in memory, print the following line backwards, from right to left
9.
Carbon paper
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The manufacture of carbon paper was formerly the largest consumer of montan wax. In 1954 the Columbia Ribbon & Carbon Manufacturing Company filed a patent for what became known in the trade as solvent carbon paper, the manufacturing process changed from a hot-melt method to a solvent-applied coating or set of coatings. It was then possible to use polyester or other plastic film as a substrate, instead of paper, in 1801 Pellegrino Turri, an Italian inventor, invented carbon paper to provide the ink for his mechanical typing machine, one of the first typewriters. Ralph Wedgwood obtained the first patent for carbon paper in 1806, currently, carbon paper is being widely used in fuel cell applications as well. This kind of paper, however, has nothing to do with the carbon paper used for copying texts. It consists of carbon microfibers manufactured into flat sheets and it is used to help as an electrode that facilitates diffusion of reactants across the catalyst layered membrane portion of membrane electrode assembly. A few specialist or remnant uses remain, in India, form-filling is on a sufficient scale that carbon paper is still widely used. As of 2013, in Canada only one company still manufactures carbon paper, in the United Kingdom one company. There have been some uses of carbon paper in art. Carbon paper is used to transfer patterns onto glass in the creation of stained glass. Carbon paper disks are used in school physics labs as parts of experiments on projectile motion or position, velocity. Carbonless copy paper Carbon Paper Being Used in Fuel Cells The Exciting History of Carbon Paper
10.
Dot matrix printing
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However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced. Each dot is produced by a metal rod, also called a wire or pin. Facing the ribbon and the paper is a guide plate named ribbon mask holder or protector. It is pierced with holes to serve as guides for the pins and this plate may be made of hard plastic or an artificial jewel such as sapphire or ruby. The portion of the containing the pins is called the print head. When running the printer, it generally prints one line of text at a time, there are two approaches to achieve this, The common serial dot matrix printers use a horizontally moving print head. The print head can be thought of featuring a vertical column of seven or more pins approximately the height of a character box. Thereby, up to 48 pins can be used to form the characters of a line while the print head moves horizontally. In a considerably different configuration, so called line dot matrix printers use a print head almost as wide as the paper path utilizing a horizontal line of thousands of pins for printing. Sometimes two horizontally slightly displaced rows are used to improve the effective dot density through interleaving, while still line-oriented, these printers for the professional heavy-duty market effectively print a whole line at once while the paper moves forward below the print head. The printing speed of serial dot matrix printers with moving heads varies from 30 to 1550 cps, in contrast to this, line matrix printers are capable of printing much more than 1000 cps, resulting in a throughput of up to 800 pages/hour. Because the printing involves mechanical pressure, both of these types of printers can create carbon copies and carbonless copies and these machines can be highly durable. A variation on the dot matrix printer was the cross hammer dot printer, the smooth cylindrical roller of a conventional printer was replaced by a spinning, fluted cylinder. The print head was a hammer, with a vertical projecting edge. Where the vertical edge of the hammer intersected the horizontal flute of the cylinder, compressing the paper, characters were built up of multiple dots. Although nearly all inkjet, thermal, and laser printers also print closely spaced dots rather than lines or characters. In 1925, Rudolf Hell invented the Hellschreiber, an early facsimile-like dot matrix-based teletypewriter device, like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method rather than synchronous transmission for communication. In 1956, while he was employed at Telefonbau und Normalzeit GmbH, the device was introduced to the Deutsche Bundespost, when Preikschat emigrated into the USA in 1957 he sold the rights to utilize the applications in any countries to TuN
11.
History of printing
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The history of printing goes back to the duplication of images by means of stamps in very early times. In both China and Egypt, the use of stamps for seals preceded the use of larger blocks. In China, India and Europe, the printing of cloth certainly preceded the printing of paper or papyrus, the process is essentially the same - in Europe special presentation impressions of prints were often printed on silk until the seventeenth century. Block printing is a technique for printing text, images or patterns used widely throughout East Asia both as a method of printing on textiles and later, under the influence of Buddhism, on paper. As a method of printing on cloth, the earliest surviving examples from China date to about 220, ukiyo-e is the best known type of Japanese woodblock art print. Most European uses of the technique on paper are covered by the term woodcut, the worlds earliest printer printed fragments to survive are from China and are of silk printed with flowers in three colours from the Han Dynasty. It reached Europe, via the Islamic world, and by around 1400 was being used on paper for old master prints, the third oldest wood-block printed book ever found after Mugujeonggwang great Dharani sutraand Hyakumantō Darani is the Diamond Sutra. It carries a date of the 13th day of the moon of the ninth year of the Xiantong era. A number of printed dhāraṇīs, however, predate the Diamond Sūtra by about two hundred years, in Buddhism, great merit is thought to accrue from copying and preserving texts. The fourth-century master listed the copying of scripture as the first of ten essential religious practices and this ‘cult of the book’ led to techniques for reproducing texts in great numbers, especially the short prayers or charms known as dhāraṇīs. Stamps were carved for printing these prayers on clay tablets from at least the seventh century, especially popular was the Pratītyasamutpāda Gāthā, a short verse text summing up Nāgārjunas philosophy of causal genesis or dependent origination. Nagarjuna lived in the centuries of the current era and the Buddhist Creed. This tradition was transmitted to China and Tibet with Buddhism, Printing text from woodblocks does not, however, seem to have been developed in India. Printing with a press was practiced in Christian Europe as a method for printing on cloth and these prints were produced in very large numbers from about 1425 onwards. Around the mid-century, block-books, woodcut books with text and images, usually carved in the same block, emerged as a cheaper alternative to manuscripts. These were all heavily illustrated works, the bestsellers of the day, repeated in many different block-book versions, the Ars moriendi. In Europe, from about 1450 they were commonly used to colour old master prints printed in black and white. This was especially the case with playing-cards, which continued to be coloured by stencil long after most other subjects for prints were left in black, stenciling back in the 27th century BCE was different
12.
Woodblock printing
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Woodblock printing is a technique for printing text, images or patterns used widely throughout East Asia and originating in China in antiquity as a method of printing on textiles and later paper. Ukiyo-e is the best known type of Japanese woodblock art print, most European uses of the technique for printing images on paper are covered by the art term woodcut, except for the block-books produced mainly in the 15th century. Prior to the invention of printing, seals and stamps were used for making impressions. The oldest of these came from Mesopotamia and Egypt. A few much larger brick stamps for marking clay bricks survive from Akkad from around 2270 BC. There are also Roman lead pipe inscriptions of some length that were stamped, however none of these used ink, which is necessary for printing, but stamped marks into relatively soft materials. In both China and Egypt, the use of stamps for seals preceded the use of larger blocks. In Europe and India, the printing of cloth certainly preceded the printing of paper or papyrus, the process is essentially the same—in Europe special presentation impressions of prints were often printed on silk until at least the 17th century. The block was cut along the grain of the wood and it is necessary only to ink the block and bring it into firm and even contact with the paper or cloth to achieve an acceptable print. The content would of course print in reverse or mirror-image, a further complication when text was involved, the art of carving the woodcut is technically known as xylography, though the term is rarely used in English. For colour printing, multiple blocks are used, each for one colour, multiple colours can be printed by keying the paper to a frame around the woodblocks. There are three methods of printing to consider, Stamping Used for many fabrics, and most early European woodcuts. These items were printed by putting paper or fabric on a table or a surface with the block on top, and pressing, or hammering. Rubbing Apparently the most common for Far Eastern printing, Used for European woodcuts and block-books later in the 15th century, and very widely for cloth. The block is placed face side up on a table, with the paper or fabric on top, the back of the paper or fabric is rubbed with a hard pad, a flat piece of wood, a burnisher, or a leather frotton. Printing in a press Presses only seem to have used in Asia in relatively recent times. Simple weighted presses may have used in Europe, but firm evidence is lacking. A deceased Abbess of Mechelen in Flanders in 1465 had unum instrumentum ad imprintendum scripturas et ymagines, cum 14 aliis lapideis printis which is probably too early to be a Gutenberg-type printing press in that location
13.
Movable type
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Movable type is the system and technology of printing and typography that uses movable components to reproduce the elements of a document usually on the medium of paper. In 1377, currently the oldest extant movable metal print book, the diffusion of both movable-type systems was, however, limited. Around 1450 Johannes Gutenberg made another version of a metal printing press in Europe, along with innovations in casting the type based on a matrix. The more limited number of characters needed for European languages was an important factor, Gutenberg was the first to create his type pieces from an alloy of lead, tin, and antimony—and these materials remained standard for 550 years. For alphabetic scripts, movable-type page setting was quicker than woodblock printing, the metal type pieces were more durable and the lettering was more uniform, leading to typography and fonts. The high quality and relatively low price of the Gutenberg Bible established the superiority of movable type in Europe, the printing press may be regarded as one of the key factors fostering the Renaissance and due to its effectiveness, its use spread around the globe. The 19th-century invention of hot metal typesetting and its successors caused movable type to decline in the 20th century, the technique of imprinting multiple copies of symbols or glyphs with a master type punch made of hard metal first developed around 3000 BC in ancient Sumer. These metal punch types can be seen as precursors of the letter punches adapted in later millennia to printing with metal type. Cylinder seals were used in Mesopotamia to create an impression on a surface by rolling the seal on wet clay and they were used to sign documents and mark objects as the owners property. By 650 BC the ancient Greeks were using larger diameter punches to imprint small page images onto coins and tokens, seals and stamps may have been precursors to movable type. A few authors even view the disc as technically meeting all definitional criteria to represent an early incidence of movable-type printing, recently it has been alleged by Jerome Eisenberg that the disk is a forgery. The Prüfening dedicatory inscription is medieval example of movable type stamps being used, yet copying books by hand was still labour-consuming. Not until the Xiping Era, towards the end of the Eastern Han Dynasty did sealing print and it was soon used for printing designs on fabrics, and later for printing texts. Woodblock printing, invented by about the 8th century during the Tang Dynasty, then carvers cut away the parts of the board that were not part of the character, so that the characters were cut in relief, completely differently from those cut intaglio. When printing, the characters would have some ink spread on them. With workers’ hands moving on the back of paper gently, characters would be printed on the paper, by the Song Dynasty, woodblock printing came to its heyday. Although woodblock printing played a role in spreading culture, there remained some apparent drawbacks. Firstly, carving the printing plate required considerable time, labour and materials, secondly, it was not convenient to store these plates, with woodblock printing, one printing plate could be used for tens of hundreds of books, playing a magnificent role in spreading culture
14.
Printing press
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A printing press is a device for applying pressure to an inked surface resting upon a print medium, thereby transferring the ink. The printing press was invented in the Holy Roman Empire by the German Johannes Gutenberg around 1440, the printing press spread within several decades to over two hundred cities in a dozen European countries. By 1500, printing presses in operation throughout Western Europe had already produced more than twenty million volumes, in the 16th century, with presses spreading further afield, their output rose tenfold to an estimated 150 to 200 million copies. The operation of a press became so synonymous with the enterprise of printing that it lent its name to a new branch of media. The sharp rise of learning and literacy amongst the middle class led to an increased demand for books which the time-consuming hand-copying method fell far short of accommodating. Technologies preceding the press led to the presss invention included, manufacturing of paper, development of ink, woodblock printing. At the same time, a number of products and technological processes had reached a level of maturity which allowed their potential use for printing purposes. The device was used from very early on in urban contexts as a cloth press for printing patterns. Gutenberg may have also inspired by the paper presses which had spread through the German lands since the late 14th century. Gutenberg adopted the design, thereby mechanizing the printing process. Printing, however, put a demand on the quite different from pressing. Gutenberg adapted the construction so that the power exerted by the platen on the paper was now applied both evenly and with the required sudden elasticity. To speed up the process, he introduced a movable undertable with a plane surface on which the sheets could be swiftly changed. The known examples range from Germany to England to Italy, however, the various techniques employed did not have the refinement and efficiency needed to become widely accepted. Gutenberg greatly improved the process by treating typesetting and printing as two separate work steps, a goldsmith by profession, he created his type pieces from a lead-based alloy which suited printing purposes so well that it is still used today. The mass production of metal letters was achieved by his key invention of a hand mould. Another factor conducive to printing arose from the existing in the format of the codex. Considered the most important advance in the history of the prior to printing itself
15.
Etching
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Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio in the metal. In modern manufacturing, other chemicals may be used on other types of material, as a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of variants such as microfabrication etching and photochemical milling it is a crucial technique in much modern technology. In traditional pure etching, a plate is covered with a waxy ground which is resistant to acid. The artist then scratches off the ground with an etching needle where he or she wants a line to appear in the finished piece. The échoppe, a tool with an oval section, is also used for swelling lines. The plate is dipped in a bath of acid, technically called the mordant or etchant. The acid bites into the metal where it is exposed, leaving behind lines sunk into the plate, the remaining ground is then cleaned off the plate. The plate is inked all over, and then the ink wiped off the surface, the plate is then put through a high-pressure printing press together with a sheet of paper. The paper picks up the ink from the lines, making a print. The process can be repeated many times, typically several hundred impressions could be printed before the shows much sign of wear. The work on the plate can also be added to by repeating the whole process, Etching has often been combined with other intaglio techniques such as engraving or aquatint. The process as applied to printmaking is believed to have been invented by Daniel Hopfer of Augsburg, Hopfer was a craftsman who decorated armour in this way, and applied the method to printmaking, using iron plates. Apart from his prints, there are two examples of his work on armour, a shield from 1536 now in the Real Armeria of Madrid. The switch to copper plates was made in Italy. On the other hand, the handling of the ground and acid need skill and experience, prior to 1100 AD, the New World Hohokam independently utilized the technique of acid etching in marine shell designs. Jacques Callot from Nancy in Lorraine made important technical advances in etching technique and he developed the échoppe, a type of etching-needle with a slanting oval section at the end, which enabled etchers to create a swelling line, as engravers were able to do. Callot also appears to have responsible for an improved, harder, recipe for the etching ground
16.
Mezzotint
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Mezzotint is a printmaking process of the intaglio family, technically a drypoint method. It was the first tonal method to be used, enabling half-tones to be produced without using line- or dot-based techniques like hatching, cross-hatching or stipple. Mezzotint achieves tonality by roughening the plate with thousands of little dots made by a tool with small teeth. In printing, the pits in the plate hold the ink when the face of the plate is wiped clean. A high level of quality and richness in the print can be achieved, the mezzotint printmaking method was invented by the German amateur artist Ludwig von Siegen. His earliest mezzotint print dates to 1642 and is a portrait of Countess Amalie Elisabeth of Hanau-Münzenberg and this was made by working from light to dark. The rocker seems to have been invented by Prince Rupert of the Rhine, a cavalry commander in the English Civil War, who was the next to use the process. Sir Peter Lely saw the potential for using it to publicise his portraits, the process was especially widely used in England from the mid-eighteenth century, to reproduce portraits and other paintings. Since the mid-nineteenth century it has relatively little used. Robert Kipniss and Peter Ilsted are two notable 20th-century exponents of the technique, M. C, British mezzotint collecting was a great craze from about 1760 to the Great Crash of 1929, also spreading to America. The favourite period to collect was roughly from 1750 to 1820, leading collectors included William Eaton, 2nd Baron Cheylesmore and the Irishman John Chaloner Smith. This became the most common method, the whole surface of a metal, usually copper, plate is roughened evenly, manually with a rocker, or mechanically. If the plate were printed at this point it would show as solid black, a burnisher has a smooth, round end, which flattens the minutely protruding points comprising the roughened surface of the metal printing plate. Areas smoothed completely flat will not hold ink at all, such areas will print white, by varying the degree of smoothing, mid-tones between black and white can be created, hence the name mezzo-tinto which is Italian for half-tone or half-painted. This is called working from dark to light, or the subtractive method, alternatively, it is possible to create the image directly by only roughening a blank plate selectively, where the darker parts of the image are to be. This is called working from light to dark, or the additive method, the first mezzotints by Ludwig von Siegen were made in this way. Especially in this method, the mezzotint can be combined with other techniques, such as engraving, on areas of the plate not roughened. The plate is put through a printing press next to a sheet of paper
17.
Aquatint
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Aquatint is an intaglio printmaking technique, a variant of etching. In intaglio printmaking, the artist makes marks on the plate that are capable of holding ink, the inked plate is passed through a printing press together with a sheet of paper, resulting in a transfer of the ink to the paper. This can be repeated a number of times, depending on the particular technique, like etching, aquatint uses the application of a mordant to etch into the metal plate. Where the engraving uses a needle to make lines that print in black. The rosin is acid resistant and typically adhered to the plate by controlled heating, the tonal variation is controlled by the level of mordant exposure over large areas, and thus the image is shaped by large sections at a time. Another tonal technique, mezzotint, begins with a surface that is evenly indented so that it will carry a fairly dark tone of ink. The mezzotint plate is then smoothed and polished to make areas carry less ink, alternatively, beginning with a smooth plate, areas are roughened to make them darker. Occasionally these two techniques are combined, the painter and printmaker Jan van de Velde IV invented the aquatint technique in Amsterdam, around 1650. The cartographer Peter Perez Burdett later introduced his secret aquatint technique to England in the 1770s, an aquatint requires a metal plate, an acid, and something to resist the acid. Traditionally copper or zinc plates were used, the artist applies a ground that will resist acid. Ground is applied by either dissolving powdered resin in spirits, applying the powder directly to the surface of the plate, in all forms of etching the acid resist is commonly referred to as the ground. An aquatint box is used to apply resin powder, the powder is at the bottom of the box, a crank or a bellows is used to blow the powder up into the air of the box. A window allows the engraver to see the density of flowing powder, when the powder covers the plate, it can be extracted from the box for the next operations. The plate is then heated, if the plate is covered with powder, the resin melts forming a fine and even coat, if it is in spirits, the spirits evaporate and the result is essentially the same. Now the plate is dipped in acid, producing an even, at this point, the plate is said to carry about a 50% halftone. This means that, were the plate printed with no further biting, at some point the artist will then etch an outline of any aspects of the drawing s/he wishes to establish with line, this provides the basis and guide for the later tone work. S/he may also have applied an acid-resistant stop out if s/he intends to keep any areas totally white and free of ink, the artist then begins immersing the plate in the acid bath, progressively stopping out any areas that have achieved the designed tonality. These tones, combined with the limited line elements, give aquatints a distinctive, also, aquatints, like mezzotints, provide ease in creating large areas of tone without laborious cross-hatching, but aquatint plates, it is noted, are generally more durable than mezzotint plates
18.
Lithography
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Lithography is a method of printing originally based on the immiscibility of oil and water. The printing is from a stone or a plate with a smooth surface. It was invented in 1796 by German author and actor Alois Senefelder as a method of publishing theatrical works. Lithography can be used to print text or artwork onto paper or other suitable material, Lithography originally used an image drawn with oil, fat, or wax onto the surface of a smooth, level lithographic limestone plate. The stone was treated with a mixture of acid and gum arabic, when the stone was subsequently moistened, these etched areas retained water, an oil-based ink could then be applied and would be repelled by the water, sticking only to the original drawing. The ink would finally be transferred to a paper sheet. This traditional technique is used in some fine art printmaking applications. In modern lithography, the image is made of a coating applied to a flexible aluminum plate. The image can be printed directly from the plate, or it can be offset, by transferring the image onto a sheet for printing. In fact, photolithography is used synonymously with offset printing, the technique as well as the term were introduced in Europe in the 1850s. Beginning in the 1960s, photolithography has played an important role in the fabrication, Lithography uses simple chemical processes to create an image. For instance, the part of an image is a water-repelling substance. Thus, when the plate is introduced to a printing ink and water mixture, the ink will adhere to the positive image. This allows a flat print plate to be used, enabling much longer, Lithography was invented by Alois Senefelder in the Kingdom of Bavaria in 1796. In the early days of lithography, a piece of limestone was used. After the oil-based image was put on the surface, a solution of gum arabic in water was applied, during printing, water adhered to the gum arabic surfaces and was repelled by the oily parts, while the oily ink used for printing did the opposite. Lithography works because of the repulsion of oil and water. The image is drawn on the surface of the print plate with a fat or oil-based medium such as a wax crayon, which may be pigmented to make the drawing visible
19.
Chromolithography
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Chromolithography is a unique method for making multi-colour prints. This type of colour printing stemmed from the process of lithography, when chromolithography is used to reproduce photographs, the term photochrome is frequently used. Lithographers sought to find a way to print on flat surfaces with the use of chemicals instead of relief or intaglio printing, hand-colouring also remained important, elements of the official British Ordnance Survey maps were coloured by hand by boys until 1875. The initial technique involved the use of multiple lithographic stones, one for each colour, depending on the number of colours present, a chromolithograph could take months to produce, by very skilled workers. However much cheaper prints could be produced by simplifying both the number of used, and the refinement of the detail in the image. Cheaper images, like advertisements, relied heavily on a black print. The process is based on the rejection of grease by water, the image is applied to stone, grained zinc or aluminium surfaces, with a grease-based crayon or ink. Limestone and zinc are two commonly used materials in the production of chromolithographs, as aluminium unfortunately corrodes easily, after the image is drawn onto one of these surfaces, the image is gummed-up with a gum arabic solution and weak nitric acid to desensitize the surface. Before printing, the image is proved before finally inking up the image with oil based transfer or printing ink, the inked image under pressure is transposed onto a sheet of paper using a flat-bed press. This describes the form of printing. The offset indirect method uses a cylinder that transfers the image from printing surface to the paper. Colours may be overprinted by using stones or plates to achieve a closer reproduction of the original. Accurate registration for multi-coloured work is achieved by the use of a key outline image, ben-Day medium, uses a raised gelatin stipple image to give tone gradation. An air-brush sprays ink to give soft edges and these are just two methods used to achieve gradations of tone. The use of twelve overprinted colours would not be considered unusual, each sheet of paper will therefore pass through the printing press as many times as there are colours in the final print. In order that each colour is placed in the position, each stone or plate must be precisely ‘registered, ’ or lined up. Chromolithographs are considered to be reproductions that are smaller than double demi, autolithographs are prints where the artist draws and perhaps prints his or her own limited number of reproductions. This is the true art form
20.
Rotary printing press
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A printing press is a device for applying pressure to an inked surface resting upon a print medium, thereby transferring the ink. The printing press was invented in the Holy Roman Empire by the German Johannes Gutenberg around 1440, the printing press spread within several decades to over two hundred cities in a dozen European countries. By 1500, printing presses in operation throughout Western Europe had already produced more than twenty million volumes, in the 16th century, with presses spreading further afield, their output rose tenfold to an estimated 150 to 200 million copies. The operation of a press became so synonymous with the enterprise of printing that it lent its name to a new branch of media. The sharp rise of learning and literacy amongst the middle class led to an increased demand for books which the time-consuming hand-copying method fell far short of accommodating. Technologies preceding the press led to the presss invention included, manufacturing of paper, development of ink, woodblock printing. At the same time, a number of products and technological processes had reached a level of maturity which allowed their potential use for printing purposes. The device was used from very early on in urban contexts as a cloth press for printing patterns. Gutenberg may have also inspired by the paper presses which had spread through the German lands since the late 14th century. Gutenberg adopted the design, thereby mechanizing the printing process. Printing, however, put a demand on the quite different from pressing. Gutenberg adapted the construction so that the power exerted by the platen on the paper was now applied both evenly and with the required sudden elasticity. To speed up the process, he introduced a movable undertable with a plane surface on which the sheets could be swiftly changed. The known examples range from Germany to England to Italy, however, the various techniques employed did not have the refinement and efficiency needed to become widely accepted. Gutenberg greatly improved the process by treating typesetting and printing as two separate work steps, a goldsmith by profession, he created his type pieces from a lead-based alloy which suited printing purposes so well that it is still used today. The mass production of metal letters was achieved by his key invention of a hand mould. Another factor conducive to printing arose from the existing in the format of the codex. Considered the most important advance in the history of the prior to printing itself
21.
Hectograph
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While the original use of the technology has diminished, it has recently been revived for use in the art world. The hectograph has been modernized and made practical for anyone to use, the special aniline dyes for making the master image came in the form of ink or in pens, pencils, carbon paper and even typewriter ribbon. Hectograph pencils and pens are still available. Various other inks have been found usable to varying degrees in the process, unlike a spirit duplicator master, a hectograph master is not a mirror image. The master is placed on the gelatin and spirits applied to transfer the ink from the master to the gelatin, after transfer of the image to the inked gelatin surface, copies are made by pressing paper against it. When a pad ceased to be useful, the gelatin could be soaked with spirits and the ink could be sponged away, a grey-colored, thick, absorbent paper pad was supplied to cover the gelatin surface for storage. This also removed ink from the surface, but took hours to do so. Care needed to be taken that the surface was kept clean. The gelatin process produced print runs of somewhere between 20 and 80 copies, depending upon the skill of the user and the quality of the original. At least eight different colors of ink were available at one time. Hectography, requiring limited technology and leaving few traces behind, has deemed useful both in low-technology environments and in clandestine circumstances where discretion was necessary. In the earlier 20th century, the process lent itself to small runs of school classroom test papers, church newsletters, prisoners-of-war at Stalag Luft III and at Colditz Castle during World War II used an improvised hectograph to reproduce documents for a planned escape attempt. It has also used, though not very extensively, as an artistic medium in printmaking. The Russian Futurists used it for book illustrations, and the German expressionist Emil Nolde made four hectographs, stephen King, in his book On Writing, talks about how he and his older brother Dave used the process to create their newspaper, Daves Rag. Before the popularization of spirit duplicators and the mimeograph, there were mechanized hectography machines that used a drum, in the final chapters of The Pothunters by P. G. Wodehouse the major characters use a jellygraph to produce a school magazine at very short notice. Wodehouse assumes his reader knows exactly what a jellygraph is and alludes to its being unattractive, I think well keep to print in future. The young, even those who had been too young to fight, were in a bad temper with their elders, as well they might be, meanwhile the old—those over sixty, say—were running in circles like hens, squawking about subversive ideas. Gordon and his friends had quite a time with their subversive ideas
22.
Offset printing
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Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface. The modern web process feeds a large reel of paper through a press machine in several parts, typically for several metres. Development of the press came in two versions, in 1875 by Robert Barclay of England for printing on tin, and in 1904 by Ira Washington Rubel of the United States for printing on paper. Lithography was initially created to be a method of reproducing artwork. This printing process was limited to use on flat, porous surfaces because the plates were produced from limestone. In fact, the word lithograph historically means an image from stone or printed from stone, tin cans were popular packaging materials in the 19th century, but transfer technologies were required before the lithographic process could be used to print on the tin. The first rotary offset lithographic printing press was created in England and this development combined mid-19th century transfer printing technologies and Richard March Hoes 1843 rotary printing press—a press that used a metal cylinder instead of a flat stone. The offset cylinder was covered with specially treated cardboard that transferred the image from the stone to the surface of the metal. Later, the covering of the offset cylinder was changed to rubber. As the 19th century closed and photography became popular, many lithographic firms went out of business, photoengraving, a process that used halftone technology instead of illustration, became the primary aesthetic of the era. Many printers, including Ira Washington Rubel of New Jersey, were using the low-cost lithograph process to produce copies of photographs, Rubel discovered in 1901—by forgetting to load a sheet—that when printing from the rubber roller, instead of the metal, the printed page was clearer and sharper. After further refinement, the Potter Press printing Company in New York produced a press in 1903, by 1907 the Rubel offset press was in use in San Francisco. The Harris Automatic Press Company also created a similar press around the same time, charles and Albert Harris modeled their press on a rotary letter press machine. One of the most important functions in the process is prepress production. This stage makes sure that all files are processed in preparation for printing. This includes converting to the proper CMYK color model, finalizing the files, Offset lithography is one of the most common ways of creating printed materials. A few of its common applications include, newspapers, magazines, brochures, stationery, compared to other printing methods, offset printing is best suited for economically producing large volumes of high quality prints in a manner that requires little maintenance. Many modern offset presses use computer-to-plate systems as opposed to the older computer-to-film work flows, advantages of offset printing compared to other printing methods include, consistent high image quality
23.
Hot metal typesetting
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In printing and typography, hot metal typesetting refers to technologies for typesetting text in letterpress printing. This method injects molten type metal into a mold that has the shape of one or more glyphs, the resulting sorts and slugs are later used to press ink onto paper. Two different approaches to mechanising typesetting were independently developed in the late 19th century, one, known as the Monotype composition caster system, produced texts with the aid of perforated paper-ribbons, all characters are cast separate. These machines could produce texts also in large-composition up to 24 point, the Super-caster, another machine produced by Monotype, was similar in function to the Thompson, Bath, pivotal and others casters but designed to produce single type for hand setting. The other approach was to cast complete lines as one slug, in this way headings could be produced to complement text produced on other machines. There is another difference between Monotype and all the slug-producing machines, a Monotype machine functions with a minimal set of matrices. Linecasters cannot function this way, and these systems need quite large magazines of matrices to be able to set a line of text with the usual character repetitions. The key feature of the Linotype is the use of molds which circulate through the machine in its various stages of operation, one type is a space band and the other is a letter matrix made of brass. The matrices are stored in one or more magazines on top of the machine while the bands are stored in a box closer to the keyboard. When the space band key near the keyboard is pressed, one of the space bands drops out of the box, the assembling elevator is adjustable for different lengths of line. Once the line approaches its correct length, the operator is aware of this by a bell or other indicator. If the line is ‘tight’ or too long, the carrying the matrices. Both scenarios, if not stopped by these safety features, usually result in a “squirt” of molten metal, encasing the matrices. Not only is it time-consuming to clean up after a squirt, therefore, it is considered very poor form for an operator to permit this to happen. When the line is assembled to the length, the operator presses down on a lever which raises the assembling elevator up into the delivery channel. The delivery channel transfers the matrices out of the assembler and into the first elevator, if the justification bar has made a full cycle and the line is still not fully justified, the second safety—the pump stop—prevents the plunger in the metal pot from going down. The space bands were an important feature of this machine, providing automatic justification of each line by equally adjusting the space between each word. Since the type used was proportional and not fixed in width, some later models had a feature that permitted the lines to be cast with the alignment to either left, right or centered
24.
Mimeograph
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The stencil duplicator or mimeograph machine is a low-cost duplicating machine that works by forcing ink through a stencil onto paper. The mimeograph process should not be confused with the spirit duplicator process, mimeographs, along with spirit duplicators and hectographs, were a common technology in printing small quantities, as in office work, classroom materials, and church bulletins. Early fanzines were printed with this technology, because it was widespread, in the late 1960s, mimeographs, spirit duplicators, and hectographs began to be gradually displaced by photocopying. Its earliest form was invented in 1874 by Eugenio de Zuccato, a young Italian studying law in London, zuccato’s system involved writing on a sheet of varnished paper with caustic ink, which ate through the varnish and paper fibers, leaving holes where the writing had been. This sheet – which had now become a stencil – was placed on a sheet of paper. The process was commercialized and Zuccato applied for a patent in 1895 having stencils prepared by typewriting, thomas Edison received US patent 180,857 for Autographic Printing on August 8,1876. The patent covered the electric pen, used for making the stencil, the word mimeograph was first used by Albert Blake Dick when he licensed Edisons patents in 1887. Dick received Trademark Registration no.0356815 for the term Mimeograph in the US Patent Office and it is currently listed as a dead entry, but shows the A. B. Dick Company of Chicago as the owner of the name. Over time, the term became generic and is now an example of a genericized trademark, in 1891, David Gestetner patented his Automatic Cyclostyle. This was one of the first rotary machines that retained the flatbed and this invention provided for more automated, faster reproductions since the pages were produced and moved by rollers instead of pressing one single sheet at a time. By 1900, two types of mimeographs had come into use, a single-drum machine and a dual-drum machine. The single-drum machine used a drum for ink transfer to the stencil. The single drum machine could be used for multi-color work by changing the drum - each of which contained ink of a different color. This was spot color for mastheads, the mimeograph became popular because it was much cheaper than traditional print - there was neither typesetting nor skilled labor involved. One individual with a typewriter and the equipment became his own printing factory. The image transfer medium was originally a stencil made from waxed mulberry paper, later this became an immersion-coated long-fibre paper, with the coating being a plasticized nitrocellulose. This flexible waxed or coated sheet is backed by a sheet of card stock. Once prepared, the stencil is wrapped around the drum of the rotary machine
25.
Photostat machine
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The Photostat machine, or Photostat, was an early projection photocopier created in the decade of the 1900s by the Commercial Camera Company, which became the Photostat Corporation. The Photostat name, which was originally a trademark of the company, became genericized, the growth of business during the industrial revolution created the need for a more efficient means of transcription than hand copying. Carbon paper was first used in the early 19th century, by the late 1840s copying presses were used to copy outgoing correspondence. One by one, other methods appeared and these included the manifold writer, developed from Christoph Scheiners pantograph and used by Mark Twain, copying baths, copying books, and roller copiers. Among the most significant of them was the Blue process in the early 1870s, stencil duplicators surfaced in 1874, and the Cyclostyle in 1891. All were manual and most involved messy fluids, the Rectigraph Company was acquired by the Haloid Company in 1935. In 1948 Haloid purchased the rights to produce Chester Carlsons xerographic equipment and in 1958 the firm was reorganized to Haloid Xerox, Haloid continued selling Rectigraph machines into the 1960s. The Photostat brand machine, differing in operation from the Rectigraph, a directory of the city from 1909 shows his Gregory Commercial Camera Company. By 1910, Gregory had co-filed a patent application with Norman W, by 1912, Photostat brand machines were in use, as evidenced by a record of one at the New York Public Library. By 1913, advertisements described the Commercial Camera Company as headquartered at Rochester, the pair filed another U. S. patent application in 1913 further developing their ideas. By 1920, distribution agency in various European markets was by the Alfred Herbert companies, for at least 40 years the brand was widespread enough that its name was genericized by the public. The Photostat Corporation was eventually absorbed by Itek in 1963, a prism was placed in front of the lens to reverse the image. After a 10-second exposure, the paper was directed to developing and fixing baths, the result was a negative print, which took about two minutes in total to produce, which could in turn be photographed to make any number of positive prints. The photographic prints produced by such machines are referred to as photostats. People who operated these machines were known as photostat operators and it was the expense and inconvenience of photostats that drove Chester Carlson to study electrophotography. In the mid-1940s Carlson sold the rights to his invention – which became known as xerography – to the Haloid Company and photostatting soon sank into history
26.
Screen printing
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Screen printing is a printing technique whereby a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and this causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed. Screen printing is also a method of print making in which a design is imposed on a screen of polyester or other fine mesh. Ink is forced into the mesh openings by the blade or squeegee and by wetting the substrate. As the screen away from the substrate the ink remains on the substrate. It is also known as silk-screen, screen, serigraphy, one color is printed at a time, so several screens can be used to produce a multicoloured image or design. There are various terms used for what is essentially the same technique, traditionally the process was called screen printing or silkscreen printing because silk was used in the process prior to the invention of polyester mesh. Currently, synthetic threads are used in the screen printing process. The most popular mesh in general use is made of polyester, there are special-use mesh materials of nylon and stainless steel available to the screen printer. There are also different types of mesh size which will determine the outcome, Screen printing first appeared in a recognizable form in China during the Song Dynasty. It was then adapted by other Asian countries like Japan, and was furthered by creating newer methods, Roy Beck, Charles Peter and Edward Owens studied and experimented with chromic acid salt sensitized emulsions for photo-reactive stencils. Commercial screen printing now uses sensitizers far safer and less toxic than bichromates, currently there are large selections of pre-sensitized and user mixed sensitized emulsion chemicals for creating photo-reactive stencils. Serigraphy is a word formed from Latin sēricum and Greek graphein. The Printers National Environmental Assistance Center says Screenprinting is arguably the most versatile of all printing processes, credit is generally given to the artist Andy Warhol for popularising screen printing as an artistic technique, identified as serigraphy, in the United States. Sister Mary Corita Kent, gained fame for her vibrant serigraphs during the 1960s and 1970s. Her works were rainbow colored, contained words that were political and fostered peace and love and caring. American entrepreneur, artist and inventor Michael Vasilantone started to use, develop, Vasilantone later filed for patent on his invention in 1967 granted number 3,427,964 on February 18,1969. The original machine was manufactured to print logos and team information on bowling garments, the Vasilantone patent was licensed by multiple manufacturers, the resulting production and boom in printed T-shirts made this garment screen printing machine popular
27.
Spirit duplicator
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A spirit duplicator was a printing method invented in 1923 by Wilhelm Ritzerfeld and commonly used for much of the rest of the 20th century. The term spirit refers to the alcohols which were a major component of the solvents used as inks in these machines. The device coexisted alongside the mimeograph, the spirit duplicator was invented in 1923 by Wilhelm Ritzerfeld. In both cases the trademark became a name for both the copiers and the process in their respective markets. Spirit duplicator technology gradually fell into disuse starting in the 1970s after the availability of low-cost, by the turn of the 21st century, the use of the technology was rare. The technology remains useful where electrical power is unavailable, or where the only remaining originals of legacy documents requiring duplication are in spirit master form. Tattoo artists use the master copies these machines produce as the design makes a very durable print on the skin that resists smudging as excess ink is wiped off during the process. The faintly sweet aroma of pages fresh off the duplicator was a feature of school life in the spirit-duplicator era. A pop culture reference to the aroma can be found in the 1982 film Fast Times At Ridgemont High, at one point a teacher distributes a duplicated schedule of class quizzes, and almost every student immediately lifts it to his or her nose and inhales. The rest of the follow suit seconds later. The duplicator used two-ply spirit masters, the first sheet could be typed, drawn, or written upon. The second sheet was coated with a layer of wax that had been impregnated with one of a variety of colorants. The pressure of writing or typing on the first sheet transferred the colored wax from the sheet to the shiny/coated back side of the first sheet. This produced the result of a sheet of carbon paper put in backwards. The two sheets were separated, and the first sheet was fastened onto the drum of the machine, with the back side facing out. There is no separate ink used in spirit duplication, as the wax transferred to the side of the first sheet contained the ink. As the paper to be printed moved through the printer, the solvent was spread across each sheet by an absorbent wick, all except black reproduced in pastel shades, pink, mint, sky blue, and so on. Spirit duplicators had the ability to print multiple colors in a single pass
28.
Phototypesetting
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The photographic paper or film is then fed into a processor, a machine that pulls the paper or film strip through two or three baths of chemicals, where it emerges ready for paste-up or film make-up. Phototypesetting machines project characters onto film for offset printing, in 1949 the Photon Corporation in Cambridge, Mass. Developed equipment based on the Lumitype of Rene Higonnet and Louis Moyroud, the Lumitype-Photon was first used to set a complete published book in 1953, and for newspaper work in 1954. Mergenthaler produced the Linofilm using a different design, and Monotype produced Monophoto, other companies followed with products that included Alphatype and Varityper. This cold-type technology could also be used in environments where hot-metal machines could not. The use of phototypesetting grew rapidly in the 1960s when software was developed to convert marked up copy, usually typed on paper tape, to the codes that controlled the phototypesetters. To provide much greater speeds, the Photon Corporation produced the ZIP200 machine for the MEDLARS project of the National Library of Medicine, the ZIP200 can produce text at 600 characters per second using high-speed flashes behind plates with images of the characters to be printed. Each character has a separate xenon flash constantly ready to fire, a separate system of optics positions the image on the page. An enormous advance was made by the mid-1960s with the development of equipment that projects the characters from CRT screens, alphanumeric Corporation produced the APS series. Rudolf Hell developed the Digiset machine in Germany, the RCA Graphic Systems Division manufactured this in the U. S. as the Videocomp, later marketed by Information International Inc. Software for operator-controlled hyphenation was a component of electronic typesetting. Early work on this topic produced paper tape to control hot-metal machines, C. J. Duncan, at the University of Durham in England, was a pioneer. Berthold successfully developed its Diatype, Diatronic, and ADS machines, Compugraphic produced phototypesetting machines in the 1970s that made it economically feasible for small publications to set their own type with professional quality. One model, the Compugraphic Compuwriter, uses a filmstrip wrapped around a drum that rotates at several hundred revolutions per minute, the filmstrip contains two fonts in one point size. To get different-sized fonts, the loads a different font strip or uses a 2x magnifying lens built into the machine. The CompuWriter II automated the lens switch and let the operator use multiple settings, other manufacturers of photo compositing machines include Alphatype, Varityper, Mergenthaler, Autologic, Berthold, Dymo, Harris, Monotype, Star/Photon, Graphic Systems Inc. Hell AG, MGD Graphic Systems, and American Type Founders, released in 1975, the Compuwriter IV holds two filmstrips, each holding four fonts. It also has a turret which has eight lenses giving different point sizes from the font, generally 8 or 12 sizes
29.
Dye-sublimation printer
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A dye-sublimation printer is a computer printer which uses heat to transfer dye onto materials such as a plastic, card, paper, or fabric. The sublimation name was first applied because the dye was considered to make the transition between the solid and gas states without going through a liquid stage and this understanding of the process was later shown to be incorrect. There is some liquifying of the dye, since then, the process is sometimes known as dye-diffusion, though this has not eliminated the original name. Many consumer and professional dye-sublimation printers are designed and used for producing photographic prints, ID cards, clothing and these are done at lower temperatures but higher pressures, particularly in all-over print processes. Some dye-sublimation printers use CMYO colors, which differs from the more recognized CMYK colors in that the black is eliminated in favour of a clear overcoating. This overcoating is also stored on the ribbon and is effectively a thin layer protects the print from discoloration from UV light. For ID card printing, text and bar codes are necessary and this overall process is then sometimes called D2T2. Dye-sublimation printing is a printing technology using full color artwork that works with polyester. The process uses the science of sublimation, in heat and pressure are applied to a solid. In sublimation printing, unique sublimation dyes are transferred to sheets of paper via liquid gel ink through a piezoelectric print head. The ink is deposited on these high-release inkjet papers, which are used for the step of the sublimation printing process. After the digital design is printed onto sublimation transfer sheets, it is placed on a heat press along with the substrate to be sublimated. In order to transfer the image from the paper to the substrate, it requires a press process that is a combination of time. The heat press applies this special combination, which can change depending on the substrate, the most common dyes used for sublimation activate at 350 degrees Fahrenheit. However, a range of 380 to 420 degrees Fahrenheit is normally recommended for optimal color, the end result of the sublimation process is a nearly permanent, high resolution, full color print. Because the dyes are infused into the substrate at the level, rather than applied at a topical level. The most common process lays one color at a time, the dye being stored on a ribbon that has each color on a separate panel. Each colored panel is the size of the medium that is being printed on, for example, tiny heating elements on the head change temperature rapidly, laying different amounts of dye depending on the amount of heat applied
30.
3D printing
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Objects can be of almost any shape or geometry and are produced using digital model data from a 3D model or another electronic data source such as an Additive Manufacturing File file. The term 3D printing originally referred to a process that deposits a binder material onto a bed with inkjet printer heads layer by layer. More recently, the term is being used in popular vernacular to encompass a variety of additive manufacturing techniques. United States and global technical standards use the term additive manufacturing for this broader sense. Early additive manufacturing equipment and materials were developed in the 1980s, but on July 16,1984 Alain Le Méhauté, Olivier de Witte and Jean Claude André filed their patent for the stereolithography process. It was three weeks before Chuck Hull filed his own patent for stereolithography, the application of French inventors were abandoned by the French General Electric Company and CILAS. The claimed reason was for lack of business perspective, Hull defined the process as a system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed, but this had been already invented by Kodama. Hulls contribution is the design of the STL file format widely accepted by 3D printing software as well as the digital slicing, the term 3D printing originally referred to a process employing standard and custom inkjet print heads. The technology used by most 3D printers to date—especially hobbyist and consumer-oriented models—is fused deposition modeling, AM processes for metal sintering or melting usually went by their own individual names in the 1980s and 1990s. But AM-type sintering was beginning to challenge that assumption, by the mid 1990s, new techniques for material deposition were developed at Stanford and Carnegie Mellon University, including microcasting and sprayed materials. Sacrificial and support materials had become more common, enabling new object geometries. The umbrella term additive manufacturing gained wider currency in the decade of the 2000s, as the various additive processes matured, it became clear that soon metal removal would no longer be the only metalworking process done under that type of control. It was during this decade that the term subtractive manufacturing appeared as a retronym for the family of machining processes with metal removal as their common theme. The term subtractive has not replaced the term machining, instead complementing it when a term that covers any removal method is needed, both terms reflect the simple fact that the technologies all share the common theme of sequential-layer material addition/joining throughout a 3D work envelope under automated control. The 2010s were the first decade in which metal end use parts such as engine brackets, agile tooling uses a cost effective and high quality method to quickly respond to customer and market needs. It can be used in hydro-forming, stamping, injection molding, as technology matured, several authors had begun to speculate that 3D printing could aid in sustainable development in the developing world. 3D printable models may be created with a computer-aided design package, via a 3D scanner, or by a digital camera. 3D printed models created with CAD result in reduced errors and can be corrected before printing, allowing verification in the design of the object before it is printed, the manual modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as sculpting
31.
Solid ink
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Solid ink is a technology used in computer printers and multifunction devices originally credited with creation by Tektronix in 1986. After Xerox acquired the Tektronix Color Printing and Imaging Division in 2000, early offerings focused on the graphic arts industry. However, after a battle with Dataproducts Corporation, Tektronix ended up paying royalties to Dataproducts for the use of the technology. The first solid ink printer, the SI-480, was developed and released to the market in 1988 by Dataproducts Corporation and this was a monochrome printer that met with limited success. The first color solid ink printer was released by Dataproducts Corporation. The Tektronix Phaser III product introduced in 1991 cost $10,000 US, as the technology improved and costs were reduced, the focus shifted to office printing environments where quality and cost efficiency are important. Solid ink printers are still expensive, Xerox remains the only producer, a wide format printer, the Phaser 600. was introduced in 1996. The Phaser 600 was capable of using roll fed or sheet fed paper up to 48 inches wide, as of July 2015, the Xerox ColorQube 8580, ColorQube 8880, ColorQube 8700, and ColorQube 8900 printers are the current solid ink printer models. Solid ink technology utilizes solid ink sticks instead of the ink or toner powder usually used in printers. Some types of solid ink printers use small spheres of solid ink, after the solid ink is loaded into the printing device, it is melted and used to produce images on paper in a process similar to offset printing. The sticks are non-toxic and safe to handle, in the mid-1990s, the president of Tektronix actually ate part of a stick of solid ink, demonstrating that they are safe to handle and presumably, eat. The medium of the ink was made from food-grade processed vegetable oils, due to the way solid ink printers put the ink onto the page, print quality is considered to be excellent, with bright colors. Excellent results can be achieved with low-quality stock, as the wax covers the stock with a glossy, almost opaque, Solid ink printers are able to print on many different types and thicknesses of media. They are much less sensitive to changes in media type than are color laser printers, a loose ink block does not leave any residual cartridge after it is consumed - only a crushable, thin, plastic packing tray and a recyclable cardboard packaging box. Solid ink printers have an advantage over ink-jet printers for situations involving intermittent use with long periods of downtime and this is because melted solid ink that has subsequently cooled and re-solidified inside the ink-delivery pathways is a normal part of printer operation. So, this cooled-and-solidified ink does not dry out, and, while the printer is not operating, the solidified wax helps to prevent oxygen and moisture from interacting with many internal parts of the ink-delivery components. Solid contaminants in ink blocks can clog printhead nozzles when using original or compatible inks, for this reason, many third-party ink manufacturers provide a guarantee and will pay for the replacement of a damaged printhead. Xerox also provides its own warranty, when the device is cold, the first page may take several minutes to print
32.
Digital printing
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Digital printing refers to methods of printing from a digital-based image directly to a variety of media. It usually refers to professional printing where small-run jobs from desktop publishing and it also allows for on-demand printing, short turnaround time, and even a modification of the image used for each impression. This results in quicker turnaround time and lower cost when using digital printing, fine art digital inkjet printing is printing from a computer image file directly to an inkjet printer as a final output. Initially, these printers were limited to glossy papers, but the IRIS Graphics printer allowed the use of a variety of papers that included traditional and non-traditional media. Substrates in fine art inkjet printmaking include traditional fine-art papers such as Rives BFK, Arches watercolor paper, treated and untreated canvas, experimental substrates, inkjet reproductions can be printed and sold individually in accordance with demand. Digital inkjet printing also allows for the output of art of all types as finished pieces or as an element in a further art piece. Experimental artists often add texture or other media to the surface of a final print, many terms for the process have been used over the years, including digigraph and giclée. Thousands of print shops and digital printmakers now offer services to painters, photographers, digital images are exposed onto true, light sensitive photographic paper with lasers and processed in photographic developers and fixers. These prints are true photographs and have continuous tone in the image detail, the archival quality of the print is as high as the manufacturers rating for any given photo paper used. In large format prints, the greatest advantage is that, since no lens is used, digital printing technology has grown significantly over the past few years with substantial developments in quality and sheet sizes. Digital printing has many advantages over traditional methods, print on Demand – digital printing is used for personalized printing for example, childrens books customized with a childs name, photo books, or any other books. Advertising – often used for banner advertising and event signage, in trade shows, in the retail sector at point of sale or point of purchase. Photos – digital printing has revolutionized photo printing in terms of the ability to retouch, architectural Design – new media that conforms to a variety of surfaces has enabled interior and exterior spaces to be transformed using digitally printed wall murals and floor graphics
33.
Electromagnet
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An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field disappears when the current is turned off, electromagnets usually consist of insulated wire wound into a coil. A current through the wire creates a field which is concentrated in the hole in the center of the coil. The main advantage of an electromagnet over a permanent magnet is that the field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a supply of current to maintain the magnetic field. Electromagnets are also employed in industry for picking up and moving heavy objects such as scrap iron. Danish scientist Hans Christian Ørsted discovered in 1820 that electric currents create magnetic fields, british scientist William Sturgeon invented the electromagnet in 1824. His first electromagnet was a piece of iron that was wrapped with about 18 turns of bare copper wire. The iron was varnished to insulate it from the windings, when a current was passed through the coil, the iron became magnetized and attracted other pieces of iron, when the current was stopped, it lost magnetization. Sturgeon displayed its power by showing that although it only weighed seven ounces, however, Sturgeons magnets were weak because the uninsulated wire he used could only be wrapped in a single spaced out layer around the core, limiting the number of turns. Beginning in 1830, US scientist Joseph Henry systematically improved and popularized the electromagnet, the first major use for electromagnets was in telegraph sounders. A portative electromagnet is one designed to just hold material in place, a tractive electromagnet applies a force and moves something. The solenoid is a coil of wire, and the plunger is made of a such as soft iron. Applying a current to the solenoid applies a force to the plunger, the plunger stops moving when the forces upon it are balanced. For example, the forces are balanced when the plunger is centered in the solenoid, the maximum uniform pull happens when one end of the plunger is at the middle of the solenoid. For units using inches, pounds force, and amperes with long, slender, solenoids, for example, a 12-inch long coil with a long plunger of 1-square inch cross section and 11,200 ampere-turns had a maximum pull of 8.75 pounds. The maximum pull is increased when a stop is inserted into the solenoid. The stop becomes a magnet that will attract the plunger, it adds little to the pull when the plunger is far away
34.
Solenoid
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A solenoid is a coil wound into a tightly packed helix. The term was invented by French physicist André-Marie Ampère to designate a helical coil, a solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field. If the purpose of the solenoid is instead to changes in the electric current. Not all electromagnets and inductors are solenoids, for example, the first electromagnet, in engineering, the term may also refer to a variety of transducer devices that convert energy into linear motion. Solenoid bolts, a type of locking mechanism, also exist. An infinite solenoid is a solenoid with infinite length but finite diameter, in short, the magnetic field inside an infinitely long solenoid is homogeneous and its strength neither depends on the distance from the axis, nor on the solenoids cross-sectional area. This is a derivation of the flux density around a solenoid that is long enough so that fringe effects can be ignored. In Figure 1, we know that the flux density vector points in the positive z direction inside the solenoid. We confirm this by applying the right hand rule for the field around a wire. If we wrap our right hand around a wire with the thumb pointing in the direction of the current, since we are dealing with a long solenoid, all of the components of the magnetic field not pointing upwards cancel out by symmetry. Outside, a similar cancellation occurs, and the field is pointing downwards. Now consider the imaginary loop c that is located inside the solenoid, by Ampères law, we know that the line integral of B around this loop is zero, since it encloses no electrical currents. We have shown above that the field is pointing upwards inside the solenoid, thus the integral of the up side 1 is equal to the integral of the down side 2. Note, though, that prohibits it from varying longitudinally. A similar argument can be applied to the loop a to conclude that the field outside the solenoid is radially uniform or constant, an intuitive argument can also be used to show that the flux density outside the solenoid is actually zero. Magnetic field lines only exist as loops, they diverge from or converge to a point like electric field lines can. The magnetic field lines follow the path of the solenoid inside. However, the volume outside the solenoid is much greater than the volume inside, now recall that the field outside is constant
35.
Sapphire
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Sapphire is a gemstone, a variety of the mineral corundum, an aluminium oxide. It is typically blue in color, but natural fancy sapphires also occur in yellow, purple, orange, the only color which sapphire cannot be is red - as red colored corundum is called ruby, another corundum variety. This variety in color is due to amounts of elements such as iron, titanium, chromium, copper. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry and they also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Sapphire is the birthstone for September and the gem of the 45th anniversary, a sapphire jubilee occurs after 65 years. Sapphire is one of the two gem-varieties of corundum, the other being ruby, although blue is the best-known sapphire color, they occur in other colors, including gray and black, and they can be colorless. A a pinkish orange variety of sapphire is called padparadscha, significant sapphire deposits are found in Eastern Australia, Thailand, Sri Lanka, China, Madagascar, East Africa, and in North America in a few locations, mostly in Montana. Sapphire and rubies are often found in the geological setting. Every sapphire mine produces a range of quality - and origin is not a guarantee of quality. For sapphire, Kashmir receives the highest premium although Burma, Sri Lanka, the cost of natural sapphires varies depending on their color, clarity, size, cut, and overall quality. For gems of exceptional quality, an independent determination from a respected laboratory such as the GIA, gemstone color can be described in terms of hue, saturation, and tone. Hue is commonly understood as the color of the gemstone, saturation refers to the vividness or brightness of the hue, and tone is the lightness to darkness of the hue. Blue sapphire exists in various mixtures of its primary and secondary hues, various tonal levels, blue sapphires are evaluated based upon the purity of their primary hue. Purple, violet, and green are the most common secondary hues found in blue sapphires, violet and purple can contribute to the overall beauty of the color, while green is considered to be distinctly negative. Blue sapphires with up to 15% violet or purple are generally said to be of fine quality, gray is the normal saturation modifier or mask found in blue sapphires. Gray reduces the saturation or brightness of the hue, and therefore has a negative effect. The 423-carat Logan sapphire in the National Museum of Natural History, in Washington, sapphires in colors other than blue are called fancy or parti colored sapphires. Fancy sapphires are found in yellow, orange, green sapphires, brown, purple
36.
Ruby
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A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum. Other varieties of gem-quality corundum are called sapphires, Ruby is one of the traditional cardinal gems, together with amethyst, sapphire, emerald, and diamond. They word ruby comes from ruber, Latin for red, the color of a ruby is due to the element chromium. The quality of a ruby is determined by its color, cut, and clarity, the brightest and most valuable red called blood-red or pigeon blood, commands a large premium over other rubies of similar quality. After color follows clarity, similar to diamonds, a stone will command a premium. Ruby is the birthstone for July and is usually more pink than garnet. The worlds most expensive ruby is the Sunrise Ruby, rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only moissanite and diamond are harder, with diamond having a Mohs hardness of 10.0, when a chromium atom replaces an occasional aluminum atom, it too loses 3 electrons to become a chromium3+ ion to maintain the charge balance of the Al2O3 crystal. However, the Cr3+ ions are larger and have electron orbitals in different directions than aluminum, the octahedral arrangement of the O2− ions is distorted, and the energy levels of the different orbitals of those Cr3+ ions are slightly altered because of the directions to the O2− ions. Those energy differences correspond to absorption in the ultraviolet, violet, if one percent of the aluminum ions are replaced by chromium in ruby, the yellow-green absorption results in a red color for the gem. Additionally, absorption at any of the above wavelengths stimulates fluorescent emission of 694-nanometer-wavelength red light, after absorbing short-wavelength light, there is short interval of time when the crystal lattice of ruby is in an excited state before fluorescence occurs. If 694-nanometer photons pass through the crystal during that time, they can stimulate more fluorescent photons to be emitted in-phase with them, thus strengthening the intensity of that red light. By arranging mirrors or other means to pass emitted light repeatedly through the crystal, all natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as silk. Gemologists use these needle inclusions found in natural rubies to distinguish them from synthetics, simulants, usually, the rough stone is heated before cutting. These days, almost all rubies are treated in some form, untreated rubies of high quality command a large premium. Some rubies show a three-point or six-point asterism or star and these rubies are cut into cabochons to display the effect properly. Asterisms are best visible with a source and move across the stone as the light moves or the stone is rotated. Such effects occur when light is reflected off the silk in a certain way and this is one example where inclusions increase the value of a gemstone
37.
Seiko Epson
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Seiko Epson Corporation, or simply Epson, is a Japanese electronics company and one of the worlds largest manufacturers of computer printers, and information and imaging related equipment. It is one of three companies of the Seiko Group, a name traditionally known for manufacturing Seiko timepieces since its founding. In 1968 the company moved its UK headquarters to Audenshaw, Manchester, after acquiring the Jones Sewing Machine Company, Daiwa Kogyo was supported by an investment from the Hattori family and began as a manufacturer of watch parts for Daini Seikosha. The company started operation in a 2, 500-square-foot renovated miso storehouse with 22 employees, in 1943, Daini Seikosha established a factory in Suwa for manufacturing Seiko watches with Daiwa Kogyo. In 1959, the Suwa Factory of Daini Seikosha was split up, Ltd, the forerunner of the Seiko Epson Corporation. The company has developed many timepiece technologies, the watches made by the company are sold through the Seiko Watch Corporation, a subsidiary of Seiko Holdings Corporation. In 1961, Suwa Seikosha established a company called Shinshu Seiki Co. as a subsidiary to supply parts for Seiko watches. In September 1968, Shinshu Seiki launched the worlds first mini-printer, in June 1975, the name Epson was coined for the next generation of printers based on the EP-101 which was released to the public. In April of the same year Epson America Inc. was established to sell printers for Shinshu Seiki Co, in June 1978, the TX-80, eighty-column dot-matrix printer was released to the market, and was mainly used as a system printer for the Commodore PET Computer. After two years of development, an improved model, the MX-80, was launched in October 1980. It was soon described in the companys advertising as the best selling printer in the United States, in November 1985, Suwa Seikosha Co. Ltd. and the Epson Corporation merged to form Seiko Epson Corporation. Shortly after in 1994, Epson released the first high resolution color inkjet printer, newer models of the Stylus series employed Epson’s special DURABrite ink. They also had two hard drives, the HD850 and the HD860 MFM interface. The specifications are reference The WINN L. ROSCH Hardware bible 3rd addition SAMS publishing, in 1994 Epson started outsourcing sales reps to help sell their products in retail stores in the United States. In 1994 Epson started the Epson Weekend Warrior sales program, the purpose of the program was to help improve sales, improve retail sales reps knowledge of Epson products and to address Epson customer service in a retail environment. Reps were assigned on weekend shift, typically around 12–20 hours a week, Epson started the Weekend Warrior program with TMG Marketing, later with Keystone Marketing Inc, then to Mosaic, and now with Campaigners INC. The Mosaic contract expired with Epson on June 24,2007 and Epson is now represented by Campaigners, the sales reps of Campaigners, Inc. are not outsourced as Epson hired rack jobbers to ensure their retail customers displayed products properly. This frees up their regular sales force to concentrate on profitable sales solutions to VARs and system integrators, in June 2003, the company became public following their listing on the 1st section of the Tokyo Stock Exchange
38.
Continuous stationery
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Continuous stationery or continuous form paper is paper which is designed for use with dot-matrix and line printers with appropriate paper-feed mechanisms. Other names for continuous stationery include fan-fold paper, sprocket feed paper, burst paper, tractor-feed paper and it can be single-ply or multi-ply, often described as multipart stationery or forms. After printing the separated sheets can be held in binders by using the holes when simply required as a record. The tear perforations may be slits, which leave noticeable serrations when torn apart. Where better appearance is necessary the perforations can be much finer, continuous form paper of all types remains in production, although largely supplanted with the introduction of fast laser printers with single-sheet feed. Continuous stationery printed on a printer is typically cheaper than laser printing although the output is of lower quality. If an impact printer is used multiple simultaneous copies can be printed on multipart forms, many laser printers can print on both sides of the paper, not possible with continuous stationery. The highest grade of continuous form paper uses a heavy bond weight similar to typing paper and it is a very lightweight bond, usually without slit perforations to remove the engagement hole strips. Common sizes, 241mm x 279mm 381mm x 279mm A decollator separates multi-part continuous form paper into separate stacks of one-part continuous form paper, a burster is a machine that separates one-part continuous form paper into separate, individual, sheets along the transverse perforations. A burster was typically used with printed continuous form paper applications such as advertising, invoices. Bursting is done by firmly gripping the second-to-last sheet while feed rollers grip the last sheet firmly, the continuous form paper then advances into the feed rollers to burst the next sheet. Large continuous documents might not be split into separate sheets, with this technique, the stack is normally flipped top to bottom or bottom to top rather than side to side. IBM cards, preprinted, optionally numbered and pre-punched, were available as continuous form cards and were used for checks, continuous form paper became widely used and well known to the general public in the 1980s due to the development of microcomputers and inexpensive dot-matrix consumer printers. Continuous form paper began to disappear from the market in the 1990s as desktop publishing. Consumers were willing to pay more to get a laser printer or inkjet printer that could produce near-typeset-quality documents and these printers accept standard size cut sheets of paper and do not require continuous form paper. Continuous form paper continues to be used in specialty commercial and industrial markets and, as of 2013, is available from large retailers of office supplies such as OfficeMax. Film perforations The Free Online Dictionary of Computing Related info at the Free On-Line Dictionary Of Computing Photo of a decollator in operation Photo of a decollator and a burster
39.
Carbon copy
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In the past, a carbon copy was the under-copy of a document created when carbon paper was placed between the original and the under-copy during the production of a document. With the advent of email, the abbreviations cc or bcc have also come to refer to sending copies of a message to recipients other than the addressee. Nowadays carbon copy is used metaphorically to refer simply to an exact copy. It is not to be confused with the carbon print family of photographic reproduction processes, a sheet of carbon paper is placed between two or more sheets of paper. The pressure applied by the writing implement to the top sheet causes pigment from the paper to make a similar mark on the copy sheet. More than one copy can be made by stacking several sheets with carbon paper between each pair, four or five copies is a practical limit. The top sheet is the original and each of the sheets is called a carbon copy. The use of carbon copies declined with the advent of photocopying, an alternative etymology is that c, was used for copy and cc, indicates the plural, just as p. means page and pp. means pages. This alternative etymology explains the frequent usage of c, when only one recipient is listed and this etymology can also explain why, even originally, cc, was used to list recipients who received typed copies and not necessarily carbon copies. The term carbon copy can be used in reference to anything that was a duplicate of an original. Carbon copy can be used as a verb with the meaning described under e-mail below related to the CC field of an e-mail message. That is, to send the message to recipients beyond the primary recipient. It is common practice to abbreviate the verb form, and many forms are acceptable, past tense forms in use are CCed, ccd, cced, cc-ed and cc, d. Present participle or imperfect forms in use include ccing, merriam-Webster uses cc, ccd and ccing, respectively. In e-mail, the abbreviation CC indicates those who are to receive a copy of a message addressed primarily to another, the list of recipients in copy is visible to all other recipients of the message. An additional BCC field is available for hidden notification, recipients listed in the BCC field receive a copy of the message and it is considered good practice to indicate to the other recipients that a new participant has been added to the list of receivers
40.
Carbonless copy paper
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Carbonless copy paper, non-carbon copy paper, or NCR paper is a type of coated paper designed to transfer information written on the front onto sheets beneath. It was developed by chemists Lowell Schleicher and Barry Green, as an alternative to paper and is sometimes misidentified as such. When pressure is applied, the dye capsules rupture and react with the clay to form a permanent mark duplicating the markings made to the top sheet. Intermediary sheets, with clay on the front and dye capsules on the back, can be used to create multiple copies, Carbonless copy paper consists of sheets of paper that are coated with micro-encapsulated dye or ink or a reactive clay. The back of the first sheet is coated with micro-encapsulated dye, the lowermost sheet is coated on the top surface with a clay that quickly reacts with the dye to form a permanent mark. Any intermediate sheets are coated with clay on top and dye on the bottom, when the sheets are written on with pressure or impact, the pressure causes the micro-capsules to break and release their dye. Since the capsules are so small, the print is very accurate. Carbonless copy paper was available in a self-contained version that had both the ink and the clay on the same side of the paper. Carbonless copy paper was first produced by the NCR Corporation, formerly, the options were to write documents more than once or use carbon paper, which was inserted between the sheet being written upon and the copy. Carbonless paper was used as business stationery requiring one or more copies of the original, such as invoices, the copies were often paper of different colors. Stationery with carbonless copy paper can be supplied collated either in pads or books bound into sets, or as loose sets, the first dye used commercially in this application was crystal violet lactone, which is widely used today. The dyes in carbonless copy papers may cause dermatitis in sensitive persons. Until the 1970s, when the use of polychlorinated biphenyls was banned due to health and environmental concerns, PCBs are readily transferred to human skin during handling of such papers, and it is difficult to achieve decontamination by ordinary washing with soap and water. In Japan, carbonless copy paper is treated as a PCB-contaminated waste. A2000 review found no irritation or sensitization on contact with carbonless copy paper produced after 1987, in most cases, good industrial hygiene and work practices should be adequate to reduce or eliminate symptoms. These include adequate ventilation, humidity, and temperature controls, proper housekeeping, minimal hand-to-mouth and hand-to-eye contact, the study also found that there were higher rates of sick leave and illness complaints at the office using large amounts of carbonless copy paper. Another study, which was published in Environmental Health Perspectives, connected chronic occupational exposure to paper dust, the average carbonless copy paper contains a high concentration of Bisphenol A, an endocrine disruptor. Scientist Test Carbonless Copy Paper for Sickening Side Effect https, //web. archive. org/web/20080829060512/http, //news. ufl. edu/1997/05/22/carbonls/
41.
Tungsten
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Tungsten, also known as wolfram, is a chemical element with symbol W and atomic number 74. The word tungsten comes from the Swedish language tung sten, which translates to heavy stone. Its name in Swedish is volfram, however, in order to distinguish it from scheelite, a hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth almost exclusively in chemical compounds. It was identified as a new element in 1781, and first isolated as a metal in 1783 and its important ores include wolframite and scheelite. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all the elements discovered, melting at 3,422 °C,6,192 °F. Its high density is 19.3 times that of water, comparable to that of uranium and gold, polycrystalline tungsten is an intrinsically brittle and hard material, making it difficult to work. However, pure single-crystalline tungsten is more ductile, and can be cut with a hard-steel hacksaw, tungstens many alloys have numerous applications, including incandescent light bulb filaments, X-ray tubes, electrodes in TIG welding, superalloys, and radiation shielding. Tungstens hardness and high density give it military applications in penetrating projectiles, tungsten compounds are also often used as industrial catalysts. Tungsten is the metal from the third transition series that is known to occur in biomolecules. It is the heaviest element known to be essential to any living organism, tungsten interferes with molybdenum and copper metabolism and is somewhat toxic to animal life. In its raw form, tungsten is a hard metal that is often brittle. If made very pure, tungsten retains its hardness, and becomes malleable enough that it can be worked easily and it is worked by forging, drawing, or extruding. Tungsten objects are commonly formed by sintering. Of all metals in pure form, tungsten has the highest melting point, lowest vapor pressure, although carbon remains solid at higher temperatures than tungsten, carbon sublimes, rather than melts, so tungsten is considered to have a higher melting point. Tungsten has the lowest coefficient of expansion of any pure metal. The low thermal expansion and high melting point and tensile strength of tungsten originate from strong covalent bonds formed between tungsten atoms by the 5d electrons, alloying small quantities of tungsten with steel greatly increases its toughness. Tungsten exists in two crystalline forms, α and β. The former has a cubic structure and is the more stable form
42.
Titanium
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Titanium is a chemical element with symbol Ti and atomic number 22. It is a transition metal with a silver color, low density. Titanium is resistant to corrosion in sea water, aqua regia, titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, and it is named by Martin Heinrich Klaproth for the Titans of Greek mythology. The metal is extracted from its principal mineral ores by the Kroll, the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride, a component of smoke screens and catalysts, and titanium trichloride, the two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is as strong as some steels, there are two allotropic forms and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the number of valence electrons and are in the same group in the periodic table. As a metal, titanium is recognized for its high strength-to-weight ratio and it is a strong metal with low density that is quite ductile, lustrous, and metallic-white in color. The relatively high melting point makes it useful as a refractory metal and it is paramagnetic and has fairly low electrical and thermal conductivity. Commercial grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, titanium is 60% denser than aluminium, but more than twice as strong as the most commonly used 6061-T6 aluminium alloy. Certain titanium alloys achieve tensile strengths of over 1400 MPa, however, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel, it is non-magnetic, machining requires precautions, because the material might gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a limit that guarantees longevity in some applications. The metal is an allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases dramatically as it is heated to this transition temperature but then falls, similar to zirconium and hafnium, an additional omega phase exists, which is thermodynamically stable at high pressures, but metastable at ambient pressures. This phase is usually hexagonal or trigonal and can be considered to be due to a soft longitudinal acoustic phonon of the β phase causing collapse of planes of atoms, like aluminium and magnesium, titanium metal and its alloys oxidize immediately upon exposure to air. Titanium readily reacts with oxygen at 1,200 °C in air and it is, however, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation. When it first forms, this layer is only 1–2 nm thick but continues to grow slowly
43.
Rudolf Hell
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Rudolf Hell was a German inventor. He was born in Eggmühl, Germany, from 1919 to 1923 he studied electrical engineering in Munich. He worked there from 1923 to 1929 as assistant of Prof. Max Dieckmann, in the same year Hell invented an apparatus called the Hellschreiber, an early forerunner to impact dot matrix printers and faxes. Hell received a patent for the Hellschreiber in 1929, in the year 1929 he founded his own company in Babelsberg, Berlin. After World War II he re-founded his company in Kiel and his company was taken over by Siemens AG in 1981 and merged with Linotype in 1990, becoming Linotype-Hell AG. Rudolf Hell died in Kiel, Germany, Hellschreiber is still in use today by Amateur Radio operators around the world. The Feld Hell Club holds monthly contests and gives out awards for hams who make contacts using this mode of communication
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Hellschreiber
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The Hellschreiber, Feldhellschreiber or Typenbildfeldfernschreiber is a facsimile-based teleprinter invented by Rudolf Hell. It has the advantage of being capable of providing intelligible communication even over very poor quality radio or cable links. The device was first developed in the late 1920s, and saw use starting in the 1930s, during WW2 it was sometimes used by the German military in conjunction with the Enigma encryption system. In the post-war era, it became common among newswire services. Hellschreiber sends a page of text as a series of vertical columns, each column is broken down vertically into a series of pixels, normally using a 7 by 7 pixel grid to represent characters. The data for a line is then sent as a series of signals to the receiver, using a variety of formats depending on the medium. At the receiver end, a tape is fed at a constant speed over a roller. Located above the roller is a cylinder with small bumps on the surface. The received signal is amplified and sent to an actuator that pulls the cylinder down onto the roller. A Hellschreiber will print each received column twice, one below the other and this is to compensate for slight timing errors that are often present in the equipment, and causes the text to slant. The received text can look like two identical texts coming out one below the other, or a line of text coming out in the middle, with chopped-off lines above, in either case, at least one whole letter can be read at all times. The original Hellschreiber machine was a device, so therefore it was possible to send half-pixels. The right ends of the loops in B, for instance, could be shifted a little, improvements that came as a result of software implementation, Depicting the received signal as shades of gray instead of monochrome, thereby making it much easier to read weak signals. Here is one mode that is international and independent of character sets, any thing that can be depicted as markings within a 7 pixels high grid. Hellschreiber has also spawned a number of variants over the years, examples of them are, PSK Hell encodes a pixels brightness in the carrier phase instead of the amplitude. Strictly speaking, its encoded in the change of the phase, a phase in the beginning of a pixel means white. It operates at 105 or 245 baud, FM Hell uses frequency modulation with a careful control of phase, essentially minimum-shift keying. Duplo Hell is a dual tone mode which sends two columns at a time at different frequencies, C/MT Hell or concurrent multitone Hell sends all rows at the same time using tones at different frequencies
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Fax
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Fax, sometimes called telecopying or telefax, is the telephonic transmission of scanned printed material, normally to a telephone number connected to a printer or other output device. The receiving fax machine interprets the tones and reconstructs the image, early systems used direct conversions of image darkness to audio tone in a continuous or analog manner. Since the 1980s, most machines modulate the audio frequencies using a digital representation of the page which is compressed to quickly transmit areas which are all-white or all-black. Scottish inventor Alexander Bain worked on chemical mechanical fax type devices and he received British patent 9745 on May 27,1843 for his Electric Printing Telegraph. Frederick Bakewell made several improvements on Bains design and demonstrated a telefax machine, the Pantelegraph was invented by the Italian physicist Giovanni Caselli. He introduced the first commercial service between Paris and Lyon in 1865, some 11 years before the invention of the telephone. In 1880, English inventor Shelford Bidwell constructed the scanning phototelegraph that was the first telefax machine to scan any two-dimensional original, previously, photographs had been sent over the radio using this process. The Western Union Deskfax fax machine, announced in 1948, was a machine that fit comfortably on a desktop. As a designer for the Radio Corporation of America, in 1924, Richard H. Ranger invented the wireless photoradiogram, or transoceanic radio facsimile, the forerunner of today’s fax machines. A photograph of President Calvin Coolidge sent from New York to London on November 29,1924 became the first photo picture reproduced by transoceanic radio facsimile, commercial use of Ranger’s product began two years later. Also in 1924, Herbert E. Ives of AT&T Corporation transmitted and reconstructed the first color facsimile, around 1952 or so, Finch Facsimile, a highly developed machine, was described in detail in a book, it was never manufactured in quantity. By the late 1940s, radiofax receivers were sufficiently miniaturized to be fitted beneath the dashboard of Western Unions Telecar telegram delivery vehicles, in the 1960s, the United States Army transmitted the first photograph via satellite facsimile to Puerto Rico from the Deal Test Site using the Courier satellite. Radio fax is still in limited use today for transmitting weather charts, in 1964, Xerox Corporation introduced what many consider to be the first commercialized version of the modern fax machine, under the name or Long Distance Xerography. This model was superseded two years later with a unit that would set the standard for fax machines for years to come. Up until this point facsimile machines were expensive and hard to operate. In 1966, Xerox released the Magnafax Telecopiers, a smaller and this unit was far easier to operate and could be connected to any standard telephone line. This machine was capable of transmitting a letter-sized document in about six minutes, the first sub-minute, digital fax machine was developed by Dacom, which built on digital data compression technology originally developed at Lockheed for satellite communication. By the late 1970s, many companies around the world, entered the fax market, very shortly after a new wave of more compact, faster and efficient fax machines would hit the market
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Teleprinter
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A teleprinter is an electromechanical typewriter that can be used to send and receive typed messages from point to point and point-to-multipoint over various types of communications channels. They were adapted to provide an interface to early mainframe computers and minicomputers, sending typed data to the computer. Some models could also be used to create punched tape for data storage, teleprinters could use a variety of different communication media. These included a pair of wires, dedicated non-switched telephone circuits, switched networks that operated similarly to the public telephone network. A teleprinter attached to a modem could also communicate through standard switched public telephone lines and this latter configuration was often used to connect teleprinters to remote computers, particularly in time-sharing environments. Teleprinters have largely replaced by fully electronic computer terminals which usually use a computer monitor instead of a printer. Teleprinters were invented in order to send and receive messages without the need for operators trained in the use of Morse code, a system of two teleprinters, with one operator trained to use a typewriter, replaced two trained Morse code operators. The teleprinter system improved message speed and delivery time, making it possible for messages to be flashed across a country with little manual intervention, in 1835 Samuel Morse devised a recording telegraph. In 1841 Alexander Bain devised a printing telegraph, by 1846, the Morse telegraph service was operational between Washington, D. C. and New York. Royal Earl House patented his printing telegraph that same year and he linked two 28-key piano-style keyboards by wire. Each piano key represented a letter of the alphabet and when pressed caused the letter to print at the receiving end. A shift key gave each main key two optional values, a 56-character typewheel at the sending end was synchronised to coincide with a similar wheel at the receiving end. It was thus an example of a data transmission system. Houses equipment could transmit around 40 instantly readable words per minute, the printer could copy and print out up to 2,000 words per hour. This invention was first put in operation and exhibited at the Mechanics Institute in New York in 1844, landline teleprinter operations began in 1849 when a circuit was put in service between Philadelphia and New York City. In 1855, David Edward Hughes introduced a machine built on the work of Royal Earl House. Émile Baudot designed a system using a five unit code in 1874, the Baudot system was adopted in France in 1877, and later extensively in France. During 1901 Baudots code was modified by Donald Murray, prompted by his development of a typewriter-like keyboard
